Switched power converters are widely used to convert between DC (direct current) source and load as well as to interface to slowly moving AC (alternating current) inputs and outputs. These uses represent one mode of operation of switched power converters. For the purpose of improving efficiency of RF (radio frequency) power amplifiers, a variable supply is used to power the amplifier. The switched power converter providing the variable supply must have a high efficiency, very low switching noise, high bandwidth and slew rate. This represents a different mode of operation for a switched power converter. Using conventional control schemes which have been developed for essentially DC sources and loads, these objectives can be met only by switching at a rate much higher than the envelope bandwidth, resulting in lower efficiency and EMI (electromagnetic interference) problems. Previous attempts have also been made to increase the bandwidth of the switched power converter by using a frequency equalizer to increase the power converter input amplitude as the input frequency increases and thereby improve the high frequency characteristics of the power converter. Unfortunately, it is impractical to manufacture in high volume a sufficiently good match between the equalizer and the power converter frequency characteristics. To increase the bandwidth of the switched power converter while still operating at a reasonable switching frequency, a method, device, phone and base station are needed specifically for tracking a dynamic variable output signal.